Study on Dynamic Evolution of the Landslide–Anchorage Structure System Under Earthquake with the Combined Finite–Discrete Element Method

The landslides caused by slope instability are very harmful and have a destructive effect on existing engineering structures such as tunnels, bridges, and houses. At present, the dynamic design of the anchorage structure is mainly based on traditional statics, which fails to fully consider the dynamic evolution process of landslide and its synergistic mechanism with anchorage structure. It is urgent to study the landslide–anchorage structure system considering both the catastrophic process and the evolution process. Based on the advanced combined finite–discrete element method (FDEM), the present study investigates the dynamic response characteristics and evolution process of the landslide–anchorage structure system by adding the dynamic strength reduction method considering the vibration deterioration effect of the structural plane and the combined one-dimensional and entity element model. The results show that the improved FDEM can accurately reproduce the characteristics of the dynamic response and the entire process of the landslide–anchorage structure system and can quantitatively evaluate the dynamic stability of the system. Through the setting of the two working conditions of unreinforced and reinforced slopes, it is verified that the addition of anchor cables can significantly reduce the dynamic response of the slopes. It is also found that the axial force is larger at the structural plane and the failure surface, and the PGA amplification factor positively correlates with the axial force of the anchor cables. The study reveals the dynamic response characteristics and evolution law of the landslide–anchorage structure system under earthquake, which can provide a scientific basis for the reasonable aseismic design of the landslide–anchorage structure system.